Ferdinand I of Bulgaria

Ferdinand I of Bulgaria (26 February 1861-10 September 1948) was Prince of Bulgaria from 7 July 1887 to 5 October 1908, succeeding Alexander of Bulgaria, and King of the Tsardom of Bulgaria from 5 October 1908 to 3 October 1918, preceding Boris III of Bulgaria.

Biography
Ferdinand Maximilian was born in Vienna, Austrian Empire on 26 February 1861 to the House of Saxe-Coburg and Gotha, the son of Prince August of Saxe-Coburg and Gotha and Clementine of Orleans. Ferdinand was a grandnephew of King Leopold I of Belgium and the nephew of Fernando II of Portugal, Victoria of Britain, Charlotte of Belgium, and Leopold II of Belgium. He served in the army of Austria-Hungary, and he was elected Prince of Bulgaria on 7 July 1887 after the Russian Empire backed a coup against Alexander of Bulgaria. During the first twenty years of his reign, he reconciled with Russia, and Bulgaria became a power in the Balkans. On 15 July 1910, he became the first head of state in history to fly in an airplane.

In 1908, Ferdinand proclaimed himself "Tsar", making Bulgaria a kingdom. Ferdinand led Bulgaria into the First Balkan War in 1912, and Bulgaria contributed the most to the war, while also suffering the bulk of the Balkan League's losses during the war with the Ottoman Empire. Ferdinand wanted for Greece and Serbia to hand over much of conquered Macedonia to Bulgaria after the war, but the two nations refused; Bulgaria fought them in the Second Balkan War, which was a Bulgarian defeat. In 1915, Ferdinand decided to ally with the German Empire and Austria-Hungary against Serbia in order to conquer more lands, entering World War I on the side of the Central Powers. Bulgaria would repel Entente forces in Greece and help in the invasion of Romania in 1916, but Ferdinand would lead Bulgaria out of the war in October 1918 as the war went badly for the Central Powers. Ferdinand abdicated on 5 October 1918, and his son Boris III of Bulgaria succeeded him as king. Ferdinand died in Coburg, West Germany in 1948 at the age of 87.